• Title/Summary/Keyword: PCBs

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Removal of PCBs in Aqueous Phase in Ultraviolet (UV), Ultrasonic (US), and UV/US Processes (자외선 및 초음파 공정에 의한 수용액 상의 PCBs 분해)

  • Lee, Dukyoung;Son, Younggyu
    • Journal of Soil and Groundwater Environment
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    • v.26 no.4
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    • pp.1-7
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    • 2021
  • The removal of PCBs (Polychlorinated biphenyls) in aqueous phase was investigated in the ultraviolet (UV) process, ultrasonics (US) process and ultraviolet/ultrasonic (UV/US) process using PCB No.7 and Aroclor 1260. For PCB No.7 relatively high removal efficiency over 90% was obtained during 20 min in the UV process and UV/US process. On the other hand, lower removal efficiency of 50 - 70% was achieved for it consisted of individual congeners of PCBs containing 3~8 of chlorine atom. It was found that the dechlorination reaction (the photolytic cleavage of C-Cl bond) was considered as a main removal mechanism in the UV process while PCBs were removed by cavitation-induced radical reaction in the US process. No significant dechlorination occurred in the US process. Consequently, it was suggested that the UV process or UV/US process was applicable for the removal of PCBs in aqueous phase in terms of the removal efficiency and operation time. In addition, the application of saturating gas such as Ar and Air could be considered to control redox condition and enhance the severity of acoustic cavitation for the removal of PCBs.

Risk Assessment of Polychrorinated Biphenyls (PCBs) through Food Intake for the Korean Population (식품 중 폴리염화비페닐 위해평가)

  • Paek, Ockjin;Suh, Junghyuk;Park, Heera;Oh, Keumsoon;Hong, Selyung;Lee, Hyunkyung;Kim, Meehye
    • Korean Journal of Food Science and Technology
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    • v.45 no.3
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    • pp.364-369
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    • 2013
  • Polychlorinated biphenyls (PCBs) have been studied during the past few decades because of their potential impacts on the environment and human health. PCBs are toxic environmental pollutants and persistent organic pollutants (POPs). This study was carried out to assess the dietary exposure and risk to PCBs for the general Korean population through food intake. Various samples (n=389) covering 28 kinds of food were collected from 5 cities in Korea. The PCB content was not detected-$182.4{\mu}g/kg$ (mean of $5.4{\mu}g/kg$) in the food. The mean dietary exposure of PCBs for the general population was 9.54 ng/kg bw/day with an intake of 0.19% of tolerable daily intake (TDI) ($5{\mu}g/kg$ bw/day). Therefore, the level of overall dietary exposure to PCBs for the Korean population through food intake is below the recommended TDI levels.

Distribution Characteristics of Polychlorinated Biphenyls in Sediments inside Jeju Harbor (제주항내 퇴적물의 PCBs 분포특성)

  • Heo, Ryun-Yong;Kam, Sang-Kyu;Cho, Eun-Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.2
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    • pp.220-227
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    • 2016
  • In this paper, polychlorinated biphenyls (PCBs) were measured in surface sediments collected three times (June, October, December, 2013), inside Jeju Harbor as major harbors of Jeju Island. The concentration of PCBs inside Jeju Harbor was in the range of 1.62~4.45 (mean) ng/g on a dry weight basis and the levels were very low. In the analysis of PCBS homologue patterns, high-chlorinated PCB congeners were dominant in surface sediments inside Jeju Harbor, indicating that their sources were originated from shipping activity. In the relationships between PCBs concentrations and particle size (mud, sand and gravel) in surface sediments, PCBs concentrations were higher in the sediments with higher mud content, indicating that higher PCBs were distributed with increasing sediments of fine gradules. The PCBs concentrations in surface sediments in this study were very low, compared with ER-L (effect range-low) and TEL (threshold effects level) among sediment quality guideleines (SQGs) applied in foreign countries, such as USA, Canada, and Australia, etc), indicating that their biological effects on the bottom organisms in marine environment were expected to be very low.

Analysis of 2,3,7,8-substituted PCDDs, PCDFs, and DL-PCBs in muscle of crucian carp (Carassius auratus and Carassius cuvieri) from major rivers and lakes (주요 하천 및 호수에 서식하는 붕어 (Carassius auratus and Carassius cuvieri) 근육에 축적된 2,3,7,8-치환 PCDDs, PCDFs 및 DL-PCBs 분석)

  • Jeong, Gi-Ho;Moon, Ji-Yong;Moon, Dong-Ho
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.484-492
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    • 2011
  • Bioaccumulation status and distribution characteristics of PCDDs, PCDFs and DL-PCBs in cruian carp collected from the four representative sites of major river systems in Korea were investigated. The recovery rates of PCDDs and PCDFs ranged from 50.6% to 88.3%, and those of DL-PCBs ranged from 52.3% to 93.2%. The mean, median and concentration range of ${\sum}$dioxins, which represents the total concentratons of PCDDs, PCDFs and DL-PCBs accumulated in the muscle of crucian carp, were 0.39, 0.14 and 0.047-1.0 pg TEQ/g wet wt., respectively. DL-PCBs were detected above the detection limit from all the samples, whereas PCDDs and PCDFs were detected from limited crucian samples. The relative contribution of DL-PCBs to ${\sum}$dioxins was remarkably larger than those for PCDDs and PCDFs. The percent contribution was 83.6% for DL-PCBs, and followed by 12.7% and 3.7% for PCDFs and PCDDs, respectively.

Separation properties of 209 PCB congeners on capillary columns and identification of PCBs congeners in aroclor standards for source identification (오염원 해석을 위한 폴리염화비페닐류(PCBs) 209 이성체의 컬럼별 분리 특성과 Aroclor 표준품의 이성체 확인)

  • Kim, Kyoung-Soo;Kim, Kyeo-Keun;Kim, Jong-Guk
    • Analytical Science and Technology
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    • v.19 no.4
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    • pp.352-364
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    • 2006
  • This study was performed to search for useful separation properties and elution orders of three GC columns (DB-1, DB-5MS, SPB-Octyl) for 209 PCBs congeners using M-1668A-0.01X-SET of the AccuStandard Inc.. In addition, to confirm the quantitative peak in peak pattern method, the IUPAC Nos. of PCBs congener peaks were identified with 4 Aroclor standards (Aroclor-1242, 1248, 1254 and 1260). The separation property of dioxin-like PCBs congeners by four columns (DB-1, DB-5MS, SP-2331 and SPB-Octyl) was excellent in SP-2331. DB-1 and SPB-Octyl columns are necessary to use with a column of other types.

Destruction and Removal of PCBs in Waste Transformer Oil by a Chemical Dechlorination Process

  • Ryoo, Keon-Sang;Byun, Sang-Hyuk;Choi, Jong-Ha;Hong, Yong-Pyo;Ryu, Young-Tae;Song, Jae-Seol;Lee, Dong-Suk;Lee, Hwa-Sung
    • Bulletin of the Korean Chemical Society
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    • v.28 no.4
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    • pp.520-528
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    • 2007
  • A practical and efficient disposal of PCBs (polychlorinated biphenyls) in waste transformer oil by a chemical dechlorination process has been reported. The transformer oil containing commercial PCB mixtures (Aroclor 1242, 1254 and 1260) was treated by the required amounts of PEG 600 (polyethylene glycol 600), potassium hydroxide (KOH) and aluminum (Al), along with different reaction temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. The relative efficiencies of PCB treatment process were assessed in terms of destruction and removal efficiency (DRE, %). Under the experimental conditions of PEG600/KOH/Al/100 oC/2hr, average DRE of PCBs was approximately 78%, showing completely removal of PCBs containing 7-9 chlorines on two rings of biphenyl which appear later than PCB no. 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to 150 oC and 240 min, average DRE of PCBs including the most toxic PCBs (PCB no. 77, 105, 118, 123 and 169) in PCB family reached 99.99% or better, with the exception of PCB no. 5 and 8 (2,3-diCB and 2,4'-diCB). In studying the reaction of PEG with PCBs, it confirmed that the process led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines. The process also permits complete recovery of treated transformer oil through simple segregating procedures.

Estimation on the application of Reference Materials for PCBs Proficiency Testing from the transformer oil (폐절연유를 이용한 숙련도 평가용 PCBs 표준물질의 적용성 평가)

  • Kim, Woo-Il;Kwon, Myung-Hee;Jeon, Tae-Wan;Kim, Dong-Hoon;Chun, Jin-Won;Sim, Ki-Tae;Yeon, Jin-Mo
    • Analytical Science and Technology
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    • v.23 no.3
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    • pp.247-254
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    • 2010
  • This study was carried out to produce Reference Materials (RMs) for Proficiency Testing (PT) of PCBs in waste analytical laboratories. Two RMs were prepared from used transformer oil samples and PCB free transformer oil by spiking PCBs standard solutions. The spiked PCB RMs were homogenized by mixing and settling up to 90 days. Homogenized concentration of PCBs with Arochlor 1254 (6 ppm), 1254:1260 (1:1) (5 ppm) were observed in 60 days stationary phase but Arochlor 1260 (3.5 mg/L) were observed in 90 days stationary phase. One-way ANOVA test were carried out and showed that the RMs were suitably homogenized, which can be used for proficiency testing. The Relative Standard Deviations (RSDs) of analytical results were 3.51~5.01% for the PCBs RMs in 10 replicates. The expanded uncertainty of PCBs analytical procedure were 0.26~0.49.

Estimation of Indicator PCBs Exposure in Infants via Breast-Feeding Period (수유기간에 따른 모유 중 Indicator PCBs 분석을 통한 영유아의 인체노출평가)

  • We, Sung-Ug;Yoon, Cho-Hee;Min, Byung-Yun
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.1
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    • pp.7-15
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    • 2012
  • The levels of indicator PCBs were determined in 132 human milk samples (Colostrum, 30th days after delivery, 60th days after delivery) collected in 2006 according to World Health Organization's (WHO) protocol. In addition, concentrations of indicator polychlorinated biphenyls (PCBs) were measured by the isotope dilution method with high resolution gas chromatograph/high resolution mass detector (HRGC/HRMS), which gave accurate and precise data for estimations of international trend and comparisons. Average daily intakes (ADIs) of all analytes were calculated. The median level of total indicator PCBs was 14 ng/g lipid, which is significantly lower than the level found in individuals from other countries. PCB congeners 138, 153 and 180 accounted for about 65% of the sum of the indicator congeners analyzed. The concentration of the most abundant PCB 153 is positively correlated with the concentration of the sum indicator PCBs (p<0.001). In this study, concentrations of total indicator PCBs significantly decreased with increasing number of children for a mother, indicating that parity and breast-feeding period an important role in the accumulation and elimination of these compounds in lactating women. The ADI for the median of total indicator PCBs for an infant was evaluated at $0.077{\mu}g/kg{\cdot}bw/day$ from birth to 6 months of age. The present study shows that concentrations of PCB 118 primipara breast milk have decreased 25~35 since 1998, and that this trend is continuing.

Biodegradation of PCBs into Contaminated Dredged Sediments (오염퇴적물에 함유된 PCBs의 생물분해 특성)

  • 안재환;김소정;지재성;배우근;황병기
    • Journal of Soil and Groundwater Environment
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    • v.9 no.2
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    • pp.41-47
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    • 2004
  • This research in the degradation of polychlorinated biphenyls(PCB) has focussed on the use of experimental enrichment cultures to obtain PCB-deading communities and identification of PCB-degrading bacteria accor야ng to pure culture. During 180 days, enrichment culture was performed to obtain PCB-degrading bacteria and initial concentration was injected 1.6 ppm,0.7 ppm, respectively. After 180 days of enrichment culture, PCBs was removed 80-87% and 57-71%. Biodegradation of PCBs was studied according to dominated PCB-degrading bacteria. Biodegraddation of PCBs was 80% in initial concentration of PCBs for 20days, enrichment cultured PCB-degrading bacteria was isolated by pure culture and it was verified to Pseudoxanthomonas sp.

Adsoption Removal of PCBs by Activated Carbon (활성탄에 의한 PCBs의 흡착제거)

  • Yu, Yong-Ho;Lee, Jong-Jig
    • Journal of the Korean Society of Safety
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    • v.21 no.1
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    • pp.59-64
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    • 2006
  • In this study, adsorption characteristics of PCBs on granular activated carbon were experimentally investigated in a batch reactor and in a fixed bed reactor. Granular activated carbon removed above 98.4% of initial concentration, 1000mg/L, of PCBs. It was estabilished that the adsorption equilibrium of PCBs on granular activated carbon was more successfully fitted by Freundlich isotherm equation in the concentration range from 1 to 1000mg/L. Because Freundlich parameter, ${\beta}$ is 0.346, removall treatment of PCBs by activated carbon accounts for the fact that toxicity reduction can be achieved through this process. Appearance time of breakthrough curve is faster with the increase flow rate and inflow concentration of liquid. The utility of granular activated carbon is enhanced with the increase of bed height and with the decrease of inflow rate.